Turbine flowmeter

Claim 1

IN COMBINATION, MEANS INCLUDING INNER AND OUTER WALLS DEFINING A RECTILINEAR FLUID FLOW CONDUIT OF UNIFORM ANNULAR CROSS-SECTION INTERRUPTED AT SPACED INTERVALS TO FORM AXIALLY SPACED APART INWARDLY OPENING ANNULAR RECESSES, A PAIR OF PERIPHERALLY BLADED AXIALLY SPACED INDEPENDENTLY ROTATABLE AXIALLY ALIGNED TURBINE ROTORS HAVING OPPOSITELY DIRECTED BLADE ANGLES AND HAVING THE BLADES THEREOF DISPOSED IN THE PATH OF FLUID FLOWING THROUGH SAID ANNULAR CONDUIT FOR MOVEMENT IN RESPONSE TO FLUID FLOW THROUGH SAID CONDUIT, THE UPSTREAM ONE OF SAID ROTORS ACTING TO IMPART A SUPPLEMENTAL DRIVING TORQUE ON THE DOWNSTREAM ONE OF SAID ROTORS AND THE DOWNSTREAM ONE OF SAID ROTORS ADAPTED TO BE CONNECTED FOR DETERMINING THE VOLUMETRIC FLOW RATE OF FLUID PASSING THROUGH SAID CONDUIT, MEANS JOURNALLING EACH OF SAID ROTORS COAXIALLY OF SAID CONDUIT WITH EACH OF SAID ROTORS BEING RADIALLY ALIGNED WITH SEPARATE ONES OF SAID RECESSES, THE BLADES OF SAID ROTORS EXTENDING RADIALLY ACROSS SAID CONDUIT AND PROJECTING INTO RESPECTIVE ONES OF SAID RECESS IN RADIALLY OVERLAPPING RELATIONSHIP TO THE INNER AND OUTER WALLS OF SAID CONDUIT WHEREBY THE FLUID STREAM CONTACTS ONLY THE BLADES AS IT PASSES THROUGH THE TURBINE ROTORS.